36 



It appears that the period of incubation varied more than the 

 duration which ranged within very narrow limits. 



To detect if possible the presence of micro-organisms in the blood 

 of animals dead with the disease, on June eighth at the time of mak- 

 ing the autops}^ numerous stab and surface inoculations weie made 

 with the blood from the heart, liver, lungs and spleen upon gelatine 

 Agar-agar and potatoes. Afterwards some were placed in the incu- 

 bator, others were kept at ordinary room temperature. In all the 

 results were negative. 



Suspecting that the attacks of the dogs upon the cattle were 

 accountable for the outbreak of tiiis obscure malady, certain experi- 

 ments which are given below were made with a view to ascertain the 

 relation of the bites of the dogs to the etiology of the disease. 



Two young, full grown rabbits were selected for the first experi- 

 ment. On June ninth at five o'clock p. m. No. 1 received the fol- 

 lowing treatment. After being properly secured, the hair clipped 

 from the forehead, it was rendered insensible by tlie use of chloro- 

 form. A small incision about one inch long was made about one- 

 eighth of an inch to the right of the median line of the skull, starting 

 at a point about the level of the eyes. After removing the perios- 

 teum a small circular opening was made through the skull which 

 exposed the covering of the brain beneath. 



A mixture, composed of a small piece (about the size of a buck- 

 shot) of the medulla of the brain of the cow examined the day 

 before, thoroughly broken up in distilled sterile water, was made. 

 By the use of a small, sterile, hypodermic syringe, 0.1 c. c. of this 

 mixture was injected beneath the dura-mater. After this operation 

 the part was carefully cleansed with a one per cent solution of car- 

 bolic acid, and the edges of the skin brought together by silk sutures. 

 Then the parts were thoroughly wet in a five per cent solution of 

 carbolic acid. After recovering from the effects of tlie anaesthetic 

 the rabbit was returned to his cage, and within a short time was eat- 

 ing and appeared as if nothing had happened. 



In the case of rabbit No. 2 the hair was cut from a spot about the 

 size of a twenty-five cent piece over the left thigli. The surface 

 skin was then treated with a solution of corrosive sublimate (one to 

 one thousand), after vvhich with a sterilized scalpel an incision about 

 one-half inch in length was made in it. Below and continuous with 

 the incision the skin was separated from the cellular tissue beneath, 

 in such a way that a pouch about one-half inch in depth was formed. 



